The present invention relates to a tire for motor cycles, which can improve the high speed durability by controlling the growth in the outer diameter of the tire during high speed running so as to prevent heat generation.
Recently, the technical development relating to motor cycles is remarkable providing motor cycles having maximum speed performances of more than 300 km/h. Accordingly, the tires mounted on such motor cycles are required to possess high speed durability.
As to the motor cycles, heretofore, in order to increase high speed performance, there are provided tires having an increase of rigidity in the tread region which is achieved by crossing cords of a carcass and a belt layer in the same way as tires for 4-wheel vehicles and providing such tires with a spiral band layer made of nylon cords wound radially outwardly of the belt layer. However, such tires as previously described increase in the tire weight, so that problems are created such that the tread region is subjected to heat generation at high speed running.
On the other hand, in order to solve such problems, a tire with a belt ply made by a belt cord wound spirally around a carcass has been suggested. However, such a belt construction is liable to be short by strength in breakage around the center region of the tread so that the resistance to shock is reduced, while in the shoulder region, it is required to further increase the resistance to compressive fatigue in relation to the bank angle. Therefore, the aforesaid problems have still not been completely eliminated.